Absorbent articles, such as disposable diapers, pant style diapers, training pants, adult incontinence undergarments, absorbent inserts, and the like absorb and contain body exudates. Such absorbent articles are intended to prevent body exudates from soiling, wetting, or otherwise contaminating clothing or other articles, such as bedding, that come into contact with a wearer of the absorbent articles. Absorbent articles may be worn for several hours in a dry state or in a urine (or other body exudates) loaded state. Efforts are made to constantly improve the fit and comfort of such absorbent articles both in the wet and dry state.
Many current absorbent articles, particularly those with airfelt (or cellulose) absorbent cores are soft and flexible when first placed in an undergarment, but become more stiff when wet. Such flexible-then stiff characteristics are seen in absorbent articles with other types of cores as well. Additionally, such airfelt (or cellulose) absorbent articles are typically bulky. Overall, traditional absorbent articles that utilize airfelt (or cellulose) are bulky and somewhat uncomfortable to wear.
Moreover, such airfelt (or cellulose) absorbent articles are inefficient to ship as the large amount of airspace in such articles (for example, between the cellulose fibers) translates into fewer absorbent articles per package and fewer packages per box. While product compression may increase packing efficiency of airfelt (or cellulose) absorbent articles, over compression reduces the absorbency effectiveness of such absorbent articles. Additionally, over compression can reduce aesthetic appeal of such absorbent articles by making the product stiff and uncomfortable to wear, or by reducing the apparent softness of individual components of the absorbent article, such as the absorbent core. Quite often, when absorbent pads containing cellulose are compressed to achieve a thin form, hard spots develop within the pads, thereby resulting in a stiffer pad and a lack of uniformity in the absorbent material.
Due to the high volume/weight ratio of traditional airfelt absorbent articles, most often shipping and packing of such articles is limited by volume instead of weight. In other words, a maximum container or vehicle volume is reached before a maximum container or vehicle weight capacity is reached when packing and/or shipping the traditional airfelt absorbent articles. This results in a shipping inefficiency due to the fact that the maximum weight bearing capacity of the container or vehicle is not being fully utilized. Essentially, shipping capacity is lost due to the amount of air within the absorbent articles that are being shipped.
Improvements have been made to absorbent articles, such as disposable diapers, by including an absorbent polymer material (sometimes known as superabsorbent polymers), such as an absorbent particulate polymer material. Absorbent particulate polymer material absorbs liquid and swells and may be particularly effective when the absorbent particulate polymer is disposed in a particular pattern, arrangement, or matrix that optimizes absorbency, fit and/or comfort. Combinations of airfelt cores and absorbent polymer materials produce diapers that are thinner, more flexible, and more absorbent than previous diapers. This type of diaper construction is now prevalent and has been in use for some time. However, these diapers are still viewed to some extent as being bulky, stiff when wet, and inefficient to ship to various store locations.
It is therefore desirable to have an even thinner, less bulky diaper that is more comfortable to use, remains flexible when wet, and more cost effective to ship to various store locations. One option to reduce bulk is to reduce or eliminate airfelt from the absorbent core. The difficulty with this approach is that it would also necessitate the absorbent particulate polymer material remaining fixed in its intended location within the absorbent article without the airfelt core to help immobilize the material, regardless of whether the absorbent article is dry or wet. Several recent publications have disclosed diapers with reduced or eliminated airfelt cores combined with immobilized absorbent particulate polymer materials. For example, an absorbent article having a substantially airfelt free absorbent core is disclosed in U.S. Patent Publication No. 2008/0312617.
While the aforementioned application discloses an absorbent core for an absorbent article having a substantially airfelt free absorbent core, a need still exists for a mechanism to avoid hard, stiff spots in the article upon compressing to fit in a package. There further exists a need for a mechanism to fully optimize product delivery and shipping for such articles (optimization from the point of view of more articles per unit volume and less packaging per number of articles packed). These types of shipping efficiencies reduce the environmental impact of shipping such articles by reducing the number of pallets and the number of trucks needed to ship the articles to various store locations and warehouses.